Electrolytically treating ores.



UNITED STATES PATENT OFFICE.

CLINTON EMERSON DOLBEAR, OF BOSTON, MASSACHUSETTS, ASSIGNOR TO AMERICAN MINING AND METAL EXTRACTION COMPANY, OF BOSTON,

MASSACHUSETTS.

ELECTROLYTICALLY TREATING ORES.

SPECIFICATION formingpart of Letters Patent No. 709,817, dated September 23, 1902.

Application filed June 3,1901. Serial No. 62,869. (No specimens.)

To all whom, it may concern:

Be it known that I, CLINTON EMERSON DOL- BEAR, a citizen of the United States, and a resident of Boston, in the county of Suflolk and State of Massachusetts, have invented certain new and useful Improvements in Electrolytically Treating Ores, of which the following is a specification.

My invention relates to a new and improved IO method of producing from raw ores metallic copper or other metals by electrolysis in the wet way.

To carry out my invention, I take a body of the metal-bearing ore that is soluble in a dissolved nitrate or in nitric acid, crush it,

and subject it to the action of a nitrate in solution or to nitric acid mixed with sulfuric acid. The object of the nitrate or nitric acid is to furnish the nitric acid radical in quan- 2c tities sufficient to accomplish the necessary chemical changes. An excess of nitric acid will not interfere with the working of the process. The sulfuric acid will not of itself attack the ores if it be in the state of a sulfid 2 5 or metallic copper; but in the presence of the nitric acid radical it will do so. If a nitrate be used-for instance, Chile niter, (sodium nitrate) the sufuric acid takes the sodium from the nitrate, liberates the nitric acid radical,

which in its turn will attack the sulfid, dissolving the base. The sulfuric acid takes the metal from the nitric acid radical, forming the sulfate. During this process the nitric acid loses oxygen, forming nitric oxid,

3 5 which under usual conditions will rise to the surface and be lost.

In the bath at the bottom of the electrolytic vat I use an insoluble anodesuch, for instance, as carbonthough I may use as anodes gold or platinum or any metal that is insoluble in the acids forming the liquid of the bath. The composition of the cathode will depend upon the metal to be plated out of the bath. For instance, if the metal to be 5 plated out is zinc the cathode will be zinc, &c.

The anode and the cathode may, if more convenient, be placed vertically in the bath,or the anode may be suspended above the cathode.

When current is flowing, the positive. terminal will liberate oxygen, which passing through the solution oxidizes the nitric oxid back to nitric acid. This is then in a condition to take up more metal, react with the sulfuric acid, and again go through the processjust described. The current, of course, at 5 5 the same time plates the metal onto the cathode, thereby in one operation giving the desired metal from the raw ore.

The sulfuric acid in combination with the nitric acid radical, whether the same is derived from a nitrate or from nitric acid directly, serves two purposes: first, as a reagent to decompose the nitrate, as stated above, and, second, to assure a reguline deposit of the metal instead of a powdered deposit of the metal, as when a nitrate or nitric acid alone is employed.

Having thus fully described my method, what I claim is 1. The method of reducing metals from their ores, which consists in dissolving the crushed ores in a nitrate of the suitable metal, adding to the mixture thus formed sulfuric acid, and subjecting the solution to the action of an electric current, whereby the metal is plated out of the solution, substantially as described.

2. The method of reducing metals from their ores, which consists in dissolving the crushed ore in a compound containing a ni- 8o tric acid radical, adding to the mixture sulfuric acid, and subjecting the resultant compound to the action of an electric current, substantially as described.

Signed at New York, in the county of New York and State of New York, this 18th day of May, A. D. 1901.

CLINTON EMERSON DOLBEAR.

Witnesses:

ALBERT STETSON, M. BUTLER. 

